A trunked communication system may be equipped with telephone interconnections to provide communication units with access to a Public Switched Telephone Network (PSTN) or Private Branch Exchange (PBX). To accomplish this, some broadcast units in the trunked communication system, support communication resources and telephone resources (interconnection repeaters), while other broadcast units support only communication resources (non-interconnection repeaters).
The types of telephone interconnection used are either matrixed or non-matrixed telephone interconnections. A matrixed telephone interconnection system can route any number (n) of telephone resources (i.e., phone lines) to any of the interconnection repeaters (m) in the system; thus forming an n*m full matrixed system. In a non-matrixed telephone interconnection system, a single phone line is directly coupled to an interconnection repeater. If the repeater is supporting a communication resource for a trunking communication, the repeater does not reroute the phone line audio to another repeater, and thus the telephone resource request goes unanswered. This is a major difference between a non-matrixed and matrixed telephone interconnection system.
Presently, in a non-matrixed telephone interconnection trunked system, an interconnection repeater handles telephone resource requests (interconnection calls) originating from a landline telephone using the directly coupled telephone resource. If this interconnection repeater does not have an available phone line, the user of the landline telephone must hang-up, request another interconnection repeater, and continue this process until an available interconnection repeater is found. Although suitable for some situations, the present technology is not suitable for all situations. There is a possibility for a landline telephone user to wait indefinitely before locating a free interconnection repeater. This wait time will depend on such variables as: the number of repeaters in the system, the length of time the repeaters are occupied, and the quickness with which the landline user can attempt to access a repeater once it becomes available. For these reasons, the present technology is typically limiting since interconnection calls cannot be transferred to an available interconnection repeater as quickly and efficiently as many users desire.
This problem is intensified when the trunked system is allocating a communication resource to a communication unit for a trunking communication, in that a central controller allocates an available communication resource from a broadcast unit in a round robin fashion of all the broadcast units. If the broadcast unit selected is an interconnection repeater, this repeater cannot support a telephone call until the trunking call is completed. This becomes inefficient when several telephone requests are waiting for an interconnection repeater while there is a non-interconnection repeater with an available communication resource that could have supported the trunking call. Thus, trunking calls and telephone calls are contending for the interconnection repeaters when contention is not necessary.
Therefore, a need exists for a method that optimizes allocation of telephone resources and communication resources with minimal resource contention.